China has become the world's largest cell phone market, with some 200 million users (spending $24 billion a year.) This has proved to be a military and intelligence nightmare for the government. Cell phones grew in popularity because the old government controlled phone company could never lay lines or install phones fast enough for the growing market. Cell phones were seen as a quick and inexpensive way to get a lot of phone service available quickly. But the government cannot monitor cell phones as easily as they could the older land line phones. Also, cell phones are easier to disrupt, or listen in on, using electronic warfare and electronic surveillance technology.